Viruses Linked to Cancer: Emerging Research Highlights Seven Key Threats
Washington, D.C. – September 16, 2025 – A growing body of research confirms a direct link between viral infections and the development of several cancers, impacting millions globally. While cancer is often associated with genetic predisposition and lifestyle factors, viruses are now recognized as significant contributors to approximately 15% of all cancer cases worldwide. Understanding these viral connections is crucial for prevention, early detection, and the development of targeted therapies.
For decades, scientists have understood the role of certain viruses in cancer development. However, recent advancements in genomic sequencing and epidemiological studies are revealing a more complete picture of the viral landscape and its impact on human health.These findings underscore the importance of vaccination, antiviral treatments, and public health initiatives aimed at controlling viral spread. The seven viruses detailed below represent a considerable, yet frequently enough overlooked, risk factor in the global fight against cancer.
1. Human Papillomavirus (HPV)
HPV is the most well-established viral cause of cancer, responsible for an estimated 5% of all cancers. Specific high-risk HPV types, such as HPV 16 and 18, are strongly linked to cervical cancer, with nearly all cases attributed to HPV infection. Beyond cervical cancer, HPV also causes cancers of the anus, vagina, vulva, penis, and oropharynx (back of the throat, including the base of the tongue and tonsils). The Centers for Disease Control and Prevention (CDC) estimates that approximately 46,000 new cancer cases are attributable to HPV each year in the United States. Vaccination against HPV is highly effective in preventing infection and subsequent cancer development.
2. Hepatitis B Virus (HBV)
chronic infection with HBV substantially increases the risk of developing liver cancer, specifically hepatocellular carcinoma. HBV causes persistent inflammation and damage to the liver, creating an habitat conducive to cancer development.Globally, HBV is estimated to cause approximately 800,000 deaths annually from liver disease and cancer. Vaccination against HBV is available and recommended for all infants and individuals at risk.
3. Hepatitis C Virus (HCV)
Similar to HBV, chronic HCV infection is a major risk factor for liver cancer. HCV also causes chronic liver inflammation and fibrosis, ultimately leading to an increased risk of hepatocellular carcinoma.An estimated 2.5 million people in the United States have chronic HCV infection, many of whom are unaware of their status. Highly effective antiviral treatments are now available that can cure HCV infection and significantly reduce the risk of liver cancer.
4. Epstein-Barr Virus (EBV)
EBV, the virus that causes infectious mononucleosis (mono), is associated with several cancers, including burkitt lymphoma, nasopharyngeal carcinoma, Hodgkin lymphoma, and certain types of gastric cancer. EBV infects B cells, a type of white blood cell, and can drive their uncontrolled proliferation. EBV is extremely common, with an estimated 90% of adults worldwide having been infected.
5. Human T-lymphotropic Virus Type 1 (HTLV-1)
HTLV-1 is a retrovirus that can cause adult T-cell leukemia/lymphoma (ATLL), a rare but aggressive cancer of the T cells. HTLV-1 is primarily transmitted through sexual contact, blood transfusions, and from mother to child during breastfeeding. ATLL is most prevalent in certain regions of Japan, the Caribbean, and parts of Africa.
6. Human Herpesvirus 8 (HHV-8)
HHV-8, also known as Kaposi’s sarcoma-associated herpesvirus (KSH
